[PATCH 2/5] clk: qcom: clk-alpha-pll: Add support for Regera PLL ops

[Satya Priya Kakitapalli]

From: Taniya Das <quic_tdas@xxxxxxxxxxx>

Regera PLL ops are required to control the Regera PLL from clock
controller drivers, thus add support for the same.

Signed-off-by: Taniya Das <quic_tdas@xxxxxxxxxxx>
Signed-off-by: Satya Priya Kakitapalli <quic_skakitap@xxxxxxxxxxx>
---
 drivers/clk/qcom/clk-alpha-pll.c | 152 ++++++++++++++++++++++++++++++++++++++-
 drivers/clk/qcom/clk-alpha-pll.h |   5 ++
 2 files changed, 156 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index 8dc3b8774b8e..f0bf282212c9 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2015, 2018, The Linux Foundation. All rights reserved.
- * Copyright (c) 2021, 2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021, 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include <linux/kernel.h>
@@ -2587,3 +2587,153 @@ const struct clk_ops clk_alpha_pll_stromer_plus_ops = {
 	.set_rate = clk_alpha_pll_stromer_plus_set_rate,
 };
 EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_plus_ops);
+
+void clk_regera_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
+			     const struct alpha_pll_config *config)
+{
+	clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), config->l);
+	clk_alpha_pll_write_config(regmap, PLL_ALPHA_VAL(pll), config->alpha);
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL(pll), config->config_ctl_val);
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U(pll), config->config_ctl_hi_val);
+	clk_alpha_pll_write_config(regmap, PLL_CONFIG_CTL_U1(pll), config->config_ctl_hi1_val);
+	clk_alpha_pll_write_config(regmap, PLL_USER_CTL(pll), config->user_ctl_val);
+	clk_alpha_pll_write_config(regmap, PLL_USER_CTL_U(pll), config->user_ctl_hi_val);
+	clk_alpha_pll_write_config(regmap, PLL_USER_CTL_U1(pll), config->user_ctl_hi1_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL(pll), config->test_ctl_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U(pll), config->test_ctl_hi_val);
+	clk_alpha_pll_write_config(regmap, PLL_TEST_CTL_U1(pll), config->test_ctl_hi1_val);
+
+	/* Set operation mode to STANDBY */
+	regmap_write(regmap, PLL_OPMODE(pll), PLL_STANDBY);
+}
+EXPORT_SYMBOL_GPL(clk_regera_pll_configure);
+
+static int clk_regera_pll_enable(struct clk_hw *hw)
+{
+	struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+	struct regmap *regmap = pll->clkr.regmap;
+	u32 val;
+	int ret;
+
+	regmap_read(regmap, PLL_MODE(pll), &val);
+
+	/* If in FSM mode, just vote for it */
+	if (val & PLL_VOTE_FSM_ENA) {
+		ret = clk_enable_regmap(hw);
+		if (ret)
+			return ret;
+		return wait_for_pll_enable_active(pll);
+	}
+
+	/* Get the PLL out of bypass mode */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_BYPASSNL, PLL_BYPASSNL);
+
+	/*
+	 * H/W requires a 1us delay between disabling the bypass and
+	 * de-asserting the reset.
+	 */
+	udelay(1);
+
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N, PLL_RESET_N);
+
+	/* Set operation mode to RUN */
+	regmap_write(regmap, PLL_OPMODE(pll), PLL_RUN);
+
+	ret = wait_for_pll_enable_lock(pll);
+	if (ret)
+		return ret;
+
+	/* Enable the PLL outputs */
+	regmap_update_bits(regmap, PLL_USER_CTL(pll), ZONDA_PLL_OUT_MASK, ZONDA_PLL_OUT_MASK);
+
+	/* Enable the global PLL outputs */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, PLL_OUTCTRL);
+
+	return 0;
+}
+
+static void clk_regera_pll_disable(struct clk_hw *hw)
+{
+	struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+	struct regmap *regmap = pll->clkr.regmap;
+	u32 val;
+
+	regmap_read(regmap, PLL_MODE(pll), &val);
+
+	/* If in FSM mode, just unvote it */
+	if (val & PLL_VOTE_FSM_ENA) {
+		clk_disable_regmap(hw);
+		return;
+	}
+
+	/* Disable the global PLL output */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_OUTCTRL, 0);
+
+	/* Disable the PLL outputs */
+	regmap_update_bits(regmap, PLL_USER_CTL(pll), ZONDA_PLL_OUT_MASK, 0);
+
+	/* Put the PLL in bypass and reset */
+	regmap_update_bits(regmap, PLL_MODE(pll), PLL_RESET_N | PLL_BYPASSNL, 0);
+
+	/* Place the PLL mode in STANDBY state */
+	regmap_write(regmap, PLL_OPMODE(pll), PLL_STANDBY);
+}
+
+static void zonda_pll_adjust_l_val(unsigned long rate, unsigned long prate,
+									u32 *l)
+{
+	u64 remainder, quotient;
+
+	quotient = rate;
+	remainder = do_div(quotient, prate);
+	*l = quotient;
+
+	if ((remainder * 2) / prate)
+		*l = *l + 1;
+}
+
+static int clk_regera_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long prate)
+{
+	struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+	unsigned long rrate;
+	u32 l, alpha_width = pll_alpha_width(pll);
+	u64 a;
+	int ret;
+
+	rrate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
+
+	ret = alpha_pll_check_rate_margin(hw, rrate, rate);
+	if (ret < 0)
+		return ret;
+
+	if (a && (a & BIT(15)))
+		zonda_pll_adjust_l_val(rate, prate, &l);
+
+	regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
+	regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
+
+	/* Wait before polling for the frequency latch */
+	udelay(5);
+
+	if (clk_hw_is_enabled(hw)) {
+		ret = wait_for_pll_enable_lock(pll);
+		if (ret)
+			return ret;
+	}
+
+	/* Wait for PLL output to stabilize */
+	udelay(100);
+
+	return 0;
+}
+
+const struct clk_ops clk_alpha_pll_regera_ops = {
+	.enable = clk_regera_pll_enable,
+	.disable = clk_regera_pll_disable,
+	.is_enabled = clk_alpha_pll_is_enabled,
+	.recalc_rate = clk_trion_pll_recalc_rate,
+	.round_rate = clk_alpha_pll_round_rate,
+	.set_rate = clk_regera_pll_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_regera_ops);
diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
index fb6d50263bb9..5bb0a07da53d 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -21,6 +21,7 @@ enum {
 	CLK_ALPHA_PLL_TYPE_LUCID = CLK_ALPHA_PLL_TYPE_TRION,
 	CLK_ALPHA_PLL_TYPE_AGERA,
 	CLK_ALPHA_PLL_TYPE_ZONDA,
+	CLK_ALPHA_PLL_TYPE_REGERA = CLK_ALPHA_PLL_TYPE_ZONDA,
 	CLK_ALPHA_PLL_TYPE_ZONDA_OLE,
 	CLK_ALPHA_PLL_TYPE_LUCID_EVO,
 	CLK_ALPHA_PLL_TYPE_LUCID_OLE,
@@ -189,6 +190,8 @@ extern const struct clk_ops clk_alpha_pll_postdiv_lucid_evo_ops;
 extern const struct clk_ops clk_alpha_pll_rivian_evo_ops;
 #define clk_alpha_pll_postdiv_rivian_evo_ops clk_alpha_pll_postdiv_fabia_ops
 
+extern const struct clk_ops clk_alpha_pll_regera_ops;
+
 void clk_alpha_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
 			     const struct alpha_pll_config *config);
 void clk_fabia_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
@@ -210,5 +213,7 @@ void clk_rivian_evo_pll_configure(struct clk_alpha_pll *pll, struct regmap *regm
 				  const struct alpha_pll_config *config);
 void clk_stromer_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
 			       const struct alpha_pll_config *config);
+void clk_regera_pll_configure(struct clk_alpha_pll *pll, struct regmap *regmap,
+			     const struct alpha_pll_config *config);
 
 #endif

-- 
2.25.1